The present invention relates to a rotation/translation converter gear unit. “Converter” relates to the conversion of a rotation into a translation. The rotation/translation converter gear unit of the present invention has a helical gear that converts a rotary drive movement into a translatory output movement, i.e., into a displacement, and a planetary gear for rotational driving of the helical gear.
Conventional helical gears may have, for example, a spindle and a spindle nut whose internal thread engages with a thread of the spindle. By rotational driving of the spindle nut or of the spindle, the other part, thus, the spindle or the spindle nut, is shifted axially. In addition to having gliding threads, there are also screw drives having rolling elements, e.g., as ball screw drives or roller screw drives. In general, the spindle nut or the spindle may also be a rotatable, axially fixed member of a helical gear having a thread, and the other part, thus, the spindle or the spindle nut, as an axially displaceable, rotatably fixed member of a helical gear having a mating thread. The thread and the mating thread engage directly and indirectly, e.g., via rolling elements, so that rotational driving of the rotatable member of the helical gear axially displaces the axially displaceable member.
Conventional planetary gears may have a sun wheel, planet wheels that mesh with the sun wheel and, in response to rotational driving, rotate and circle the sun wheel, and having an internal gear, concentrically encircling the sun wheel, with which the planet wheels likewise mesh and in which they rotate in response to rotational driving. The planet wheels are mounted eccentrically and rotatably on a planet carrier that is disposed co-axially with respect to the sun wheel and the internal gear.